JPS6347530Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heating device using exhaust heat for automobiles.

Prior Art Cooling water after cooling the engine is guided to an exhaust heat exchanger installed in the engine exhaust system, heated by exhaust heat, and then guided to the heater core of a heating unit to warm the air flowing through the heater core. In a heating system using exhaust heat for a vehicle that blows air into a room, the exhaust pipe of the engine is configured to be branched into an exhaust pipe provided with the exhaust heat exchanger and a bypass exhaust pipe that bypasses the exhaust heat exchanger. The applicant had previously developed a switch valve that was installed at the branch part and configured to operate the switch valve using a heater blower switch, a coolant temperature switch, and an engine warm-up detection switch. It is published as Publication -26007.

Problems to be solved by the invention The above-mentioned prior art can significantly improve the heating effect by using the cooling heat of the engine and the exhaust heat of the exhaust gas as heat sources for warming up, and can also use the heating Even when the engine is not in use, when the engine is warmed up, exhaust gas flows through the exhaust pipe on the side where the exhaust heat exchanger is installed, and the exhaust heat warms the engine cooling water, which can significantly shorten the warm-up time. It can produce extremely valuable effects.

The present invention is an improvement on this prior art idea.

Means to Solve the Problems The present invention has been developed so that the operating range of the switch that controls the energization of the EGR solenoid of the EGR device, which has been commonly used as one of the measures to purify engine exhaust gas, is the same as when the engine has warmed up. The operating range of the switch for controlling the lighting of the engine warning lamp, which warns the driver to fully open the engine valve after the engine has started and warmed up, is approximately the same as the previous range, and the operating range of the switch that controls the lighting of the engine warning lamp, which warns the driver to fully open the engine valve after the engine has been warmed up, is the range after the engine has warmed up. Focusing on the above range, the warm-up detection switch in the exhaust heat utilizing heating system of the prior art is shared with the switch for controlling the energization to the EGR solenoid and the lighting control of the cooling warning lamp. That is.

Effect In the above, one warm-up detection switch
Energization control to the EGR solenoid, lighting control of the cooling warning lamp, and shortening of engine warm-up time using exhaust heat utilization heating system can all be performed accurately, reducing the number of parts and significantly reducing costs. You can measure down.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

In FIG. 1, 1 is an engine, 2 is a radiator, and 3 is a water pump. The cooling water supplied by the water pump 3 absorbs heat from the engine 1 while flowing through the water jacket of the engine 1. The cooling water flows into the radiator 2 through the water channel a, radiates heat in the radiator 2, and is sent back to the engine 1 through the water channel b. By circulating the cooling water in this way, the engine 1 is cooled. It's summery.

Furthermore, by opening the heater cooker 8, the cooling water (warm water) that has taken away the heat from the engine 1 flows from the water channel c into the exhaust heat exchanger 5 provided in the exhaust pipe, where it is further heated by exhaust heat. The cooling water flows through the rear seat heater core 61 and the front seat heater core 62 through the water channel d, and the heater cores 61 and 62 heat the heating air to make it warm air, and then it passes through the water channel b again. A so-called heating circulation path for engine cooling water is formed, which is supplied to the engine 1 to cool the engine.

The exhaust pipe 4 of the engine 1 is connected to the exhaust heat exchanger 5
The exhaust pipe 41 is branched into a bypass exhaust pipe 42 that bypasses the exhaust heat exchanger 5, and a switching valve 9 is provided at the branching portion of both exhaust pipes 41 and 42.

Reference numerals 71 and 72 indicate heater blowers for the rear seat and the front seat, respectively. Note that the embodiment shown in FIG. 1 illustrates an automobile in which a heating unit is provided for the rear seats and a heating unit for the front seats, so the heater core and heater blower are shown separately for the rear seats and the front seats. The present invention can also be applied to a type of automobile in which the entire vehicle interior is heated with one heater core and one heater blower, and in the following description, both types are included and will be represented by the symbol heater core 6. The heater blower will be represented by the symbol 7.

The switching valve 9 is a heater blower switch 1.
0. Switching is controlled by the operation of an engine cooling water temperature switch 12 and a warm-up detection switch 13 that detects whether the engine 1 is warmed up.

That is, when the heater cooker 8 is opened (the heater cooker switch 20 is turned on) and the heater blower switch 10 is turned on, current flows from the power supply 14 to the motor 7a of the heater blower 7 via the ignition switch 15, and the heater blower 7 is driven to rotate. At the same time, the exhaust heat solenoid valve 16 is also energized, the exhaust heat solenoid valve 16 is opened, the intake negative pressure of the engine intake pipe 17 is guided to the vacuum actuator 18, and the switching valve 9 opens the exhaust pipe 41. , the bypass exhaust pipe 42 is closed, and almost all of the exhaust gas flows to the exhaust pipe 41 side, and the heater core 6
This increases the temperature of the cooling water flowing through the system, increasing the temperature of the heating air.

In addition, when the temperature of the engine cooling water exceeds a predetermined value (for example, 90°C or higher) during the heating operation using exhaust heat as described above, the water temperature switch 12 is turned on and the relay (normally closed) 11 is turned on. Exhaust heat solenoid valve 16 as off
The switching valve 9 switches to the side where the bypass exhaust pipe 42 is opened, and almost all of the exhaust gas flows through the bypass exhaust pipe 42, stopping the heating of the cooling water by the exhaust heat, and is directed to the radiator 2. The motor 19a of the forced ventilation radiator fan 19 is driven to rotate, thereby reducing the load on the radiator 2 and preventing overheating.

Furthermore, when the engine 1 is warmed up (for example, when the engine coolant temperature is 60°C or lower), even if the heater blower switch 10 is off and the heater cock switch 20 is off, the warm-up detection switch 13 prevents the engine from being discharged. Current flows through the thermal solenoid valve 16, the vacuum actuator 18 operates, and the switching valve 9 switches to open the exhaust pipe 41 side where the exhaust heat exchanger 5 is installed, and the engine cooling water is turned off. The exhaust gas flows into the exhaust heat exchanger 5 through the waterway c, where it is heated, and then is sent to the engine 1 again from the waterway d through the bypass waterway e, thereby significantly shortening the engine warm-up time.

In the above-mentioned exhaust heat utilization type heating device,
In the present invention, as shown in FIG. 2, a thermoswitch for controlling an EGR solenoid 21 and a cooling warning lamp 22, which will be described later, is used as the warm-up detection switch 13.

In other words, as one of the exhaust gas purification measures for automobile engines, a part of the exhaust gas is recirculated into the combustion chamber of the engine, thereby lowering the maximum combustion temperature in the cylinder and suppressing the generation of NOx (nitrogen oxides). has been commonly used in the past, and this device is generally referred to as an EGR device, and the amount of exhaust gas recirculated has conventionally been controlled by an EGR solenoid operated based on engine cooling water temperature and vehicle speed.

In general, in automobiles, when the engine cooling water temperature exceeds a predetermined value after the engine has been started and the engine valve remains closed even after warm-up has been completed, a bright light will illuminate to remind the driver to fully open the engine valve. A warning warning light is usually provided.

In this invention, the set temperature range of the engine cooling water that should be energized to the EGR solenoid of the EGR device is approximately
60℃ or less, and the set temperature range of the engine cooling water that should make the engine cooling lamp brightly illuminate is approximately 60℃ or higher, and in both cases, the engine cooling water temperature at the end of engine warm-up (approximately 60℃) is the limit. Focusing on the fact that the temperature is set within a range between less than and more than that, one thermo switch controls the running warning lamp, controls the energization of the EGR solenoid, and controls the energization of the exhaust heat solenoid valve 16. The configuration allows the user to perform the following steps.

As shown in FIG. 2, the warm-up detection switch 13
One terminal 13a is on until warm-up is completed (for example, when the engine coolant temperature is less than 60°C), and after warm-up is completed (for example, when the engine coolant temperature is 60°C or higher). is the other terminal 1
3b side is turned on, and the exhaust heat solenoid valve 16 is configured so that energization is controlled by the heater control switch 20, the heater blower switch 10, etc., and the warm-up detection switch 13
The EGR solenoid 21 is configured so that the energization is controlled by turning on and off terminal 13a of the EGR solenoid 21, and the EGR solenoid 21 is energized by the vehicle speed switch 23, which is turned on when the vehicle speed exceeds 45 km/h, and also controls the heating. Electricity is controlled by turning on and off the terminal 13a of the engine detection switch 13. Furthermore, the ignition warning lamp 22 is connected to the ignition switch 24, which turns on when the ignition valve is not fully open, and the warm-up detection switch. The lighting is controlled by turning on and off the 13b terminal of 13.

In Figure 2, D1, D2, D3, D4, D5
are current backflow prevention elements, and these current backflow prevention elements allow the EGR solenoid 21 and the exhaust heat solenoid valve 16 to be controlled independently without influencing each other.

In the above, when the engine has not been warmed up yet after starting, that is, when the engine cooling water is below 60°C, the warm-up detection switch 13 is switched to the terminal 13a.
is on and the heater switch is on.
Even when heating is not in use with the heater blower 10 turned off, the power supply 14 connects the ignition switch 15, relay 11, exhaust heat solenoid valve 16, and terminal 13a of the warm-up detection switch 13.
The circuit leading to the ground is closed, the switching valve 9 is activated, and the exhaust pipe 41 equipped with the exhaust heat exchanger 5 is opened, the exhaust gas flows through the exhaust pipe 41, and the engine cooling water is heated by the exhaust heat. As mentioned above, the warm-up time of the engine can be significantly shortened, and
EGR solenoid 21 is also energized to control EGR. Since EGR control using the EGR solenoid 21 is conventionally known, detailed explanation will be omitted.

During this warm-up operation, the air passage valve is naturally constricted, so the air passage switch 24 is on, but the warm-up detection switch 1
Since the terminal 13b of No. 3 is off, current flows through the lighting lamp 22 through the resistor R, resulting in a dimly lit state.

After warm-up is complete, for example, the engine coolant temperature is 60℃.
When the warm-up detection switch 13 exceeds the terminal 13a,
is turned off, and terminal 13b is turned on. Then, the power to the exhaust heat solenoid valve 16 is cut off, the switching valve 9 is switched, and the exhaust gas is allowed to pass through the bypass exhaust pipe 42, and the heating of the engine coolant by the exhaust heat is stopped, and the EGR solenoid 2
The power to terminal 13b is also cut off, and instead terminal 13b
is turned on, so a short circuit that connects directly to the ground without going through the resistor R is closed, and the Chiyoke waking lamp 22 changes from its previous dimly lit state to its brightly lit state, and the Chiyoke valve is fully opened. When the driver fully opens the check valve based on the warning, the check switch 24 is turned off and the check warning lamp 22 is turned off.

In this way, the single warm-up detection switch 13 can accurately control the exhaust warning lamp 22, the EGR solenoid 21, and the exhaust heat solenoid valve 16.

In the illustrated embodiment, an example is shown in which the switching control of the switching valve 9 is performed by the vacuum actuator 18 and the exhaust solenoid valve 16 that controls the negative pressure supplied to the vacuum actuator 18. In addition, for example, an electromagnetic solenoid device is used instead of the exhaust heat solenoid valve 16, and when the heater control switch 20 and the heater blower switch 10 are on, and when the warm-up detection switch 13
When the terminal 13a is on, an electromagnetic solenoid device may be operated to switch the switching valve 9 directly or via a link mechanism.

Effects of the invention As described above, according to the invention, the exhaust pipe of an engine is configured to branch into an exhaust pipe provided with an exhaust heat exchanger and a bypass exhaust pipe that bypasses the exhaust heat exchanger, and the exhaust pipe is switched to the branched part. When a valve is installed, the heater cock is opened, and the heater blower switch is turned on, the switching valve operates to open the exhaust pipe equipped with the exhaust heat exchanger and close the bypass exhaust pipe, thereby cooling the engine. Water flows into the exhaust heat exchanger, is heated by exhaust heat, and then returns to the engine through the heater core to improve the heating effect, and also maintains the engine cooling water temperature at the set value during heating as described above. A cooling water temperature switch is provided that operates the switching valve to open the bypass exhaust pipe when the temperature exceeds the temperature above, and when the engine warms up, a warm-up detection switch operates to switch the switching valve to the exhaust heat exchanger. In the exhaust heat utilization type heating system, which aims to shorten the warm-up time by heating the engine cooling water with exhaust heat in the exhaust heat exchanger by switching to open the exhaust pipe where the The feature is that the detection switch is used in common with the switch for controlling the energization to the EGR solenoid and the lighting control of the lighting warning lamp. It is possible to achieve a significant reduction in the number of parts and a corresponding significant cost reduction without impairing the purification function, the water cooling function, etc. in the slightest, and this can bring about great practical effects.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a heating system showing an example of a heating device using exhaust heat according to the present invention, and FIG. 2 is a circuit diagram showing an embodiment of the present invention. 1...Engine, 2...Radiator, 3...Water pump, 4...Exhaust pipe, 5...Exhaust heat exchanger, 6...Heater core, 7...Heater blower,
8...Heater cock, 9...Switching valve, 10...
... Heater blower switch, 11 ... Relay, 12
... Cooling water temperature switch, 13 ... Warm-up detection switch, 16 ... Exhaust heat solenoid valve, 18 ... Vacuum actuator, 20 ... Heater control switch, 21 ... EGR solenoid, 22 ...
Chiyoke warning lamp, 23... Vehicle speed switch, 24... Chiyoke switch, D1, D2,
D3, 4D, D5... Current backflow prevention element.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A heater cock is opened in the cooling water circulation path where the cooling water after cooling the engine radiates heat in a radiator and then flows into the engine again. An exhaust heat exchanger installed in the engine exhaust pipe is provided with a heating circulation path for cooling water, which is further heated by an exhaust heat exchanger installed in the exhaust pipe, and then flows through the heater core of the heating unit and flows back into the engine. A bypass exhaust pipe that bypasses the exhaust heat exchanger is configured to branch, and a switching valve is provided at the branch, and the switching valve is operated so that when the heater stock is opened and the heater blower switch is turned on, the exhaust pipe provided with the exhaust heat exchanger is opened. a circuit that operates the switching valve to open the bypass exhaust pipe when the engine cooling water temperature exceeds a set value, and a warm-up detection switch that detects when the engine is warming up. A circuit for operating a switching valve to open the exhaust pipe provided with the heat exchanger is provided, and the warm-up detection switch is also used as a switch for controlling energization of the EGR solenoid and lighting of the exhaust warning lamp. A heating device using exhaust heat for a vehicle, characterized in that it is shared. (2) The warm-up detection switch has one terminal that remains on while the engine is not warmed up and the other terminal that remains on after the engine has warmed up. The energizing circuit and the energizing circuit for the member that operates the switching valve to open the exhaust pipe provided with the exhaust heat exchanger are respectively connected to one terminal of the warm-up detection switch via a current backflow prevention element. 2. A heating device using exhaust heat for an automobile according to claim 1, wherein the current supply circuit for the cooling waking lamp is connected to the other terminal of the warm-up detection switch. (3) A current backflow prevention element is provided in the circuit that operates the switching valve to open the exhaust pipe equipped with the exhaust heat exchanger when the heater cooker is opened and the heater blower switch is turned on. A heating device using exhaust heat for an automobile according to claim 1 or 2 of the utility model registration claim.